diff --git a/src/target/rp.c b/src/target/rp.c
index 5556b45..3c4c193 100644
--- a/src/target/rp.c
+++ b/src/target/rp.c
@@ -514,9 +514,9 @@ static bool rp_cmd_reset_usb_boot(target *t, int argc, const char **argv)
 {
 	struct rp_priv_s *ps = (struct rp_priv_s *)t->target_storage;
 	if (argc > 2) {
-		ps->regs[1] = atoi(argv[2]);
+		ps->regs[1] = strtoul(argv[2], NULL, 0);
 	} else if (argc < 3) {
-		ps->regs[0] = atoi(argv[1]);
+		ps->regs[0] = strtoul(argv[1], NULL, 0);
 	} else {
 		ps->regs[0] = 0;
 		ps->regs[1] = 0;